1. Field of the Invention
The present invention relates to a slide surface construction, and particularly, to a slide surface construction comprised of an aggregate of Fe crystals and having a corrosion resistance.
2. Description of the Related Art
In order to improve the frictional resistance, such conventionally known slide surface constructions include an Fe-plated layer, for example, which is provided on outer peripheral surfaces of a land portion and a skirt portion of a piston body made of an aluminum alloy in a piston for an internal combustion engine.
However, the known slide surface construction suffers from a problem that under existing circumstances where speed and output of the internal combustion engine have tended to increase, the known slide surface construction is not sufficient in oil retaining property, namely, oil retention and seizure resistance are poor due to a relatively smooth slide surface thereof.
Therefore, the assignee of the present invention has developed a slide surface construction having a large number of pyramid-shaped Fe crystals in a slide surface thereof (for example, see Japanese Patent Application Laid-open No. 174089/94).
If the slide surface construction is formed in this manner, adjacent pyramid-shaped Fe crystals assume mutually biting states and hence, the slide surface takes on an intricate aspect comprising a large number of fine crests, a large number of fine valleys formed between the crests, and a large number of fine swamps formed due to mutual biting of the crests. Therefore, the slide surface construction has a good oil retention. Thus, the seizure resistance of the slide surface construction is enhanced.
However, as a result of various reviews of that slide surface construction, it has been made clear that the slide surface construction has a relatively low corrosion resistance, and hence, in order to permit the slide surface construction of the piston to maintain a good oil retention, for example, in a sliding environment in which salt as a road anti-freezing agent is drawn into the engine along with air, it is necessary for the slide surface construction to have an excellent corrosion resistance.
There is also a conventionally known cylinder sleeve formed of a cast iron, for example, in a diesel engine or a methanol engine for a vehicle. In the diesel engine, sulfuric acid is produced during burning of fuel, and in the methanol engine, formic acid is produced during burning of fuel. For this reason, it is required that the cylinder sleeve has a high corrosion resistance and thus a high acid resistance. However, in the present situation, a means for meeting such a requirement has not been developed.